The present invention is generally related to a pressure transducer and more particularly to a pressure transducer employing a fluid as oil for transfering pressure to a diaphragm.
Essentially, pressure transducers are well-known and many different types exist in the prior art. Many of these transducers employ piezoresistive elements or sensors which are disposed on a diaphragm and which when subjected to a force or pressure exhibit a change in resistance.
Essentially, such devices have been used with oil which oil or fluid is employed as a force transmitting medium. In such devices the pressure applied to the diaphragm or transducer is normally quite large and therefore these devices employ a metal diaphragm as a force collector. The metal diaphragm communicates with a silicon pressure transducer through an oil filled reservoir which is manifested by an internal hollow in the transducer housing.
In any event, the force imparted on the metal diaphragm can cause pressures inside the transducer which are large enough to dislodge the terminal pins and to rupture or break the transducer assembly. In fact the most common area of destruction due to large pressures in transducers is the virtual "blow out" of the terminal pins. This problem has not been adequately solved by any prior art device. There are of course transducers which have been designed and used for high pressure or differential pressure operation using oil filled cavities.
U.S. Pat. No. 4,177,680 entitled Dual Pressure Sensor issued on Dec. 11, 1979 to Coleman. This patent employs two oil filled enclosures which are separated by a substrate and which transducer provides a differential output upon the application of a pressure.
Other patents which involves pressure transducers operating in various environments are U.S. Pat. No. 2,507,501, U.S. Pat. No. 3,507,099 and U.S. Pat. No. 4,068,527.
The above patents are representative of certain types of pressure transducers but in any manner do not solve or disclose the above noted problem which is manifested by the rupture or force removal of terminal pins when a fluid filled transducer is subjected to high pressure.